CHEMICAL COMPOSITION. xli 



of diseased and healthy persons. The quantity is very small. The form of 

 sugar is that known as glucose or grape sugar. 



Colouring Principles. A yellow or greenish-yellow colouring principle, 

 supposed to be the same as that of the bile, has been found by various 

 chemists in the blood of persons affected with jaundice, and, according to 

 Lecanu and Denis, a certain amount of it may be detected even in healthy 

 blood. The colouring matter which gives a pale yellowish tint to ordinary 

 serum does not, however, exhibit the reactions of bile-pigments. 



Odoriferous Matters. Denis describes three. 1. One combined with fat, 

 smelling like garlick. 2. One supposed to depend on a volatile oil, with an 

 odour said to be of peculiar character in each species of animal, and to be 

 heightened by adding sulphuric acid to the blood. 3. One of a variable 

 character, derived from the food. Schmidt found that the blood of only 

 three animals yielded an odour distinctive of the species. 



Salts. 1. Having soda and potash as bases, combined with lactic, 

 carbonic, phosphoric, sulphuric, and fatty acids. Also chlorides of sodium 

 and potassium, the former in large proportion. Schmidt has pointed out 

 that the potash-salts exist almost exclusively in the blood- corpuscles and the 

 soda salts principally in the serum. In the corpuscles there are principally 

 chloride of potassium and phosphate of potass : in the serum, chloride of 

 sodium, and phosphate of soda. The following table (giving the mean of 

 eight experiments) exhibits the relative quantities of potassium and sodium, 

 and of phosphoric acid and chlorine, in the blood-corpuscles and plasma. 



100 parts of Inorganic Matters. 



The Table shows that the chlorides are, relatively to the phosphates, in much 

 larger quantity in the plasma than in the blood-corpuscles ; and that the phosphates 

 are, relatively to the chlorides, in much larger proportion in the blood-corpuscles than 

 in the plasma. 



2. Lactate of ammonia. 3. Salts with earthy bases, viz. , lime and magnesia 

 with phosphoric, carbonic, and sulphuric acids. 



The earthy salts are for the most part associated with the albumen, but partly with 

 the crassamentum. As they are obtained by calcination, it has been suspected that 

 the phosphoric and sulphuric acids may be in part formed by oxidation of the phos- 

 phorus and sulphur of the organic compounds. Nasse found in 1000 parts of blood 

 4 to 7 of alkaline, and 0'53 of earthy salts. 



Mean Composition. The following statement of the mean composition of 

 human venous blood is from Lecanu. (Etudes chimiques sur le sang 

 huniain, Paris, 1837.) 



